Keratoconus, lenticonus, lentiglobus , microspherophakia &

keratoconus / keratoglobus/ lenticonus etc detail ……...

1. Keratoconus, Lenticonus, Lentiglobus , Microspherophakia & Lens Coloboma Dr. Sharad SCEH, Lahan , O.A 2 nd year student class

2. keratoconus

3. Keratoconus (conical cornea) is a non-inflammatory bilateral (85%) ectatic condition of cornea in its axial part. It usually starts at puberty and progresses slowly .

4. Etiopathogenesis. developmental condition & degenerative condition hereditary dystrophy and endocrine anomaly. Essential pathological changes are progressive thinning and ectasia which occur as a result of defective synthesis of mucopolysaccharide and collagen tissue .

5. Clinical features & Symptoms. Patient presents with a defective vision due to progressive myopia and irregular astigmatism . Sign : 1. Window reflex is distorted. 2. Placido disc examination shows irregularity of the circles . 3. Slit-lamp examination may show thinning and ectasia of central cornea 4. Fleischer’s ring at the base of cone, folds in Descemet’s and Bowman’s membranes .

6. Signs of Keratoconus : 5. On retinoscopy a yawning reflex (scissor reflex ) & irregular astigmatism . 6. On distant direct ophthalmoscopy : oil droplet reflex 7. Munson’s sign, i.e., localised bulging of lower lid when patient looks down is positive . 8. Keratometry. Normal average keratometric values are 45 D. In keratoconus keratometric values are increased. keratoconus is graded as: mild (< 48 D), moderate (48–54 D), and severe (>54 D).

7. morphological classification Nipple cone has a small size (<5 mm) and steep curvature. • Oval cone is larger (5–6 mm) and ellipsoid in shape. • Globus cone is very large (>6 mm) and globe like

8. Complications Keratoconus may be complicated by development of acute hydrops due to rupture of Descemet’s membrane . Lacrimation Photophobia Blepharospasm

9. Association Ocular conditions like Ectopia lentis , congenital cataract, aniridia Retinitis pigmentosa & vernal keratoconjunctivitis (VKC) Marfan’s syndrome Down’s syndrome Ehlers-Danlos syndrome,

10. Treatment : 1. Spectacle correction may improve vision in early cases. 2. Contact lenses ( rigid gas permeable /RGP lens ) usually improve the vision in early cases. Scleral contact lens (Rose-K) may be useful. 3. INTACS the intracorneal ring segments , are reported to be useful . 4. Corneal collagen cross linking with riboflavin (CXL or C3R) and UV-A rays may slow the progression . 5. . Keratoplasty may be required in later stages. Deep anterior lamellar keratoplasty (DALK) or penetrating keratoplasty (PK )

11. Keratoconus :

12. KERATOGLOBUS : Keratoglobus is a rare, noninflammatory corneal ectasia characterized by diffuse protrusion and thinning of the cornea .

13. It is nonprogressive and inherited as an autosomal recessive trait . It must be differentiated from congenital buphthalmos , where increased corneal size is associated with raised intraocular pressure, angle anomaly and/or cupping of optic disc.

14. How keratoconus is differentiated from keratoglobus Keratometry readings can reach 50-60 D. Fleischer rings, Vogt striae, and anterior stromal scarring are not typical, but Descemet membrane thickening and folds are common.

15. Management of keratoglobus No medical therapy has been discovered to treat the underlying pathology. Instead, attention is focused on complications such as acute hydrops. Hypertonic saline, cycloplegia, and bandage soft contact lenses are the mainstay of treatment. Aqueous suppressants have also been proposed to decrease stromal uptake of fluid . SURGERY : penetrating keratoplasty (PK) was one of the first surgical procedures attempted . A second surgical option involves the use of DSAEK donor tissue to patch the host endothelium .

16. Lenticonus : It is a rare congenital anomaly of the eye characterized by a conical protrusion on the crystalline lens capsule and the underlying cortex . It can reach a diameter of 2 to 7 mm. The conus may occur anteriorly or posteriorly .

17. anterior & posterior lenticonus

18. Association